I've recently become addicted to Peter Pepper's Ice Cream Factory, it's tough but once you get the hang of it it's a pretty fun game and has a lot of the gameplay assets of Burgertime, I can make it to like the 8th level now.
Victory is another I like, it's sort of like Defender except with 360 degree rotation by the player, like PPIF I think poor hardware design was responsible for its obscurity.